Earlier springs are having a wide impact, the study shows

Springtime in the UK is starting on average 11 days earlier than 30 years ago, causing natural food chains to become disrupted, a study suggests.

Predators seem to be slower than organisms further down the food chains to respond to the seasonal shifts, according to a team of UK researchers.

The findings are based on more than 25,500 records of 726 marine, terrestrial and freshwater species.

The study has been published in the journal Global Change Biology.

"If biological events at different levels within the food chains are changing at different rates, it is possible that we are seeing a de-synchronisation," explained lead author Stephen Thackeray, an ecologist at the Centre for Ecology and Hydrology (CEH).

Environment-wide shifts

The study, carried out by 12 research groups, showed - for the first time - an acceleration in seasonal timings (phenology) at an environment-wide scale.

From a phenological viewpoint, what we need to do is understand the processes well enough in order to make projections of future changes Dr Stephen Thackeray, Centre for Ecology and Hydrology

Previous studies had identified the trend of spring arriving earlier, but had focused on single species or a small grouping, generally plants.

"We have shown that the acceleration is an average pattern across the terrestrial, marine and freshwater environments," Dr Thackeray told BBC News.

He explained that the data, covering the period between 1976 and 2005, showed the change was "most pronounced" among organisms at the bottom of the food chains.

"[This] could have an impact on the survival of the predators and affect the status of their populations.

"You often find that predatory organisms - those at the top of the food chain - frequently time their reproduction in a way that synchronises food availability with the arrival of their offspring."

The researchers said that if the patterns identified in their study were indicative of future trends, the breakdown in synchronisation could disrupt "the functioning, persistence and resilience of many ecosystems and have a major impact on ecosystem services".

"My co-authors and I are now in the very early stages of working on more detailed case studies that, hopefully, shed some light on the detailed processes," Dr Thackeray added.

"From a phenological viewpoint, what we need to do is understand the processes well enough in order to make projections of future changes."

On average, each decade within the study saw spring advance by 3.9 days

Dr Thackeray said that he hoped the study would be used as a benchmark for similar studies to be carried out in other parts of the world.

source: http://news.bbc.co.uk/2/hi/science/nature/8506363.stm